Copy and Swap idiom

CppUG_CopySwap.h

#include <cstring>
#include <iostream>

class foo
{
    public:
        explicit foo(const char* arg) : cstring{new char[std::strlen(arg)+1]} {
            std::strcpy(cstring, arg);
        }
        ~foo() {
            delete[] cstring;
        }
        foo(const foo& other) : cstring{new char[std::strlen(other.cstring) + 1]} {
            std::strcpy(cstring, other.cstring);
        }
        foo(foo&& other) noexcept : cstring{other.cstring} {
            other.cstring = nullptr;
        }
        
        // Copy assignment and Move assignment
        foo& operator=(foo other) // pass by value
        {
            std::swap(cstring, other.cstring);
            return *this;
        }
    private:
        char* cstring;
};